MDEV-9077 add sys_schema from https://github.com/mysql/mysql-sys

scripts/sys_schema/functions/quote_identifier.sql

@@ -0,0 +1,71 @@
+-- Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; version 2 of the License.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program; if not, write to the Free Software
+-- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+DROP FUNCTION IF EXISTS quote_identifier;
+
+DELIMITER $$
+
+-- https://dev.mysql.com/doc/refman/5.7/en/identifiers.html
+-- Maximum supported length for any of the current identifiers in 5.7.5+ is 256 characters.
+-- Before that, user variables could have any length.
+--
+-- Based on Paul Dubois' suggestion in Bug #78823/Bug #22011361.
+CREATE DEFINER='root'@'localhost' FUNCTION quote_identifier(in_identifier TEXT)
+    RETURNS TEXT CHARSET UTF8
+    COMMENT '
+             Description
+             -----------
+
+             Takes an unquoted identifier (schema name, table name, etc.) and
+             returns the identifier quoted with backticks.
+
+             Parameters
+             -----------
+
+             in_identifier (TEXT):
+               The identifier to quote.
+
+             Returns
+             -----------
+
+             TEXT
+
+             Example
+             -----------
+
+             mysql> SELECT sys.quote_identifier(''my_identifier'') AS Identifier;
+             +-----------------+
+             | Identifier      |
+             +-----------------+
+             | `my_identifier` |
+             +-----------------+
+             1 row in set (0.00 sec)
+
+             mysql> SELECT sys.quote_identifier(''my`idenfier'') AS Identifier;
+             +----------------+
+             | Identifier     |
+             +----------------+
+             | `my``idenfier` |
+             +----------------+
+             1 row in set (0.00 sec)
+            '
+    SQL SECURITY INVOKER
+    DETERMINISTIC
+    NO SQL
+BEGIN
+    RETURN CONCAT('`', REPLACE(in_identifier, '`', '``'), '`');
+END$$
+
+DELIMITER ;